This whole "soulmate" secret that science has unlocked, though, isn't actually all that complicated. According to a study out of the University of Illinois, figuring out if you'll marry your significant other is as easy as seeing how well they remember your history together. Turns out, couples who remember the history of the relationship better are more likely to eventually tie the knot.

In the study, researchers followed 232 unmarried heterosexual couples over the course of nine months. Throughout that time, the couples once a month were asked to report on how the relationship was going, rate their chances of getting married, and to recall past stages in the relationship. Interestingly, the couples who wound up getting more serious were also the couples where both partners were better able to remember the relationship's history.

In other words, whether or not he or she remembers your birthday might not actually matter as much as whether or not they remember your first fight. Go figure.

The study only used data from heterosexual couples, but it should theoretically hold true for LGBT couples as well, though of course getting married might be trickier or involve a road trip if you're not in a state where marriage equality is legal yet. But even for couples (gay or straight) who aren't into the idea of marriage, the basic principle here makes sense: if you're more serious about the relationship and its long-term future, you'll also have a better handle on its past. After all, the scientists point out, when you're considering the idea of making a lifelong commitment to someone, it's important to remember the actual facts of the relationship, good and bad.

People whose relationships were tanking or stagnating, on the other hand, tended to misremember their relationship trajectory in ways that made things seem better than they were. As a coping mechanism, it's not the worst, but it's certainly not conducive to making healthy relationship decisions.

The takeaway here, of course, is not to grill your significant other on every detail about your past together in hopes of gauging how serious they are. Their ability to remember details is actually kind of beside the point; after all, this study was only looking at recall for more general relationship trends. The real message probably is that people in a relationship that's going somewhere are honest with themselves about their relationship's past.

Though actually, being honest with yourself is good advice for anything in general. Save the lies for other people.